england-and-wales
Yes.
Fraud
If done intentionally, it's fraud under Section 2 of the Fraud Act 2006:
(1) A person is in breach of this section if he — (a) dishonestly
makes a false representation, and (b)intends, by making the
representation — (i) to make a gain for himself or another, or (ii) to
cause loss to another or to expose another to a risk of loss.
(2) A representation is false if — (a) it is untrue or misleading, and
(b) the person making it knows that it is, or might be, untrue or
misleading.
(3) “Representation” means any representation as to fact or law,
including a representation as to the state of mind of - (a) the person
making the representation, or (b) any other person.
Consumer regulations
It's also illegal under the Consumer Protection from Unfair Trading Regulations 2008. Regulation 3 provides:
(1) Unfair commercial practices are prohibited.
(3) A commercial practice is unfair if — (a) it contravenes the
requirements of professional diligence; and (b) it materially distorts
or is likely to materially distort the economic behaviour of the
average consumer with regard to the product.
(4) A commercial practice is unfair if — (a) it is a misleading action
under the provisions of regulation 5; [...]
Regulation 5 contains further provisions relating to misleading actions:
(1) A commercial practice is a misleading action if it satisfies the
conditions in either paragraph (2) or paragraph (3).
(2) A commercial practice satisfies the conditions of this paragraph —
(a) if it contains false information and is therefore untruthful in
relation to any of the matters in paragraph (4) or if it or its
overall presentation in any way deceives or is likely to deceive the
average consumer in relation to any of the matters in that paragraph,
even if the information is factually correct; and (b) it causes or is
likely to cause the average consumer to take a transactional decision
he would not have taken otherwise.
(4) The matters referred to in paragraph (2)(a) are — [...] (k) the
consumer's rights or the risks he may face. [...]
"Transactional decision" is defined in Regulation 2 and includes a decision of whether to exercise a contractual right in relation to the product:
2 (1) In these Regulations [...] “transactional decision” means any
decision taken by a consumer, whether it is to act or to refrain from
acting, concerning — [...] (b) whether, how and on what terms to
exercise a contractual right in relation to a product.
The contractual right in question here is the right, implied into the contract by statute, for the quality of the goods to be satisfactory under Section 9 of the Consumer Rights Act 2015:
(1) Every contract to supply goods is to be treated as including a
term that the quality of the goods is satisfactory.
Section 19 sets out your statutory rights if the trader is in breach of the above
term.
The applicable offences are found in Regulations 8 and 9:
8 (1) A trader is guilty of an offence if — (a) he knowingly or
recklessly engages in a commercial practice which contravenes the
requirements of professional diligence under regulation 3(3)(a); and
(b) the practice materially distorts or is likely to materially
distort the economic behaviour of the average consumer with regard to
the product under regulation 3(3)(b).
8 (2) For the purposes of paragraph (1)(a) a trader who engages in a
commercial practice without regard to whether the practice contravenes
the requirements of professional diligence shall be deemed recklessly
to engage in the practice, whether or not the trader has reason for
believing that the practice might contravene those requirements.
9. A trader is guilty of an offence if he engages in a commercial practice which is a misleading action under regulation 5 otherwise
than by reason of the commercial practice satisfying the condition in
regulation 5(3)(b).
I find it hard to believe that that someone whose full-time job is dealing with customer complaints can't be aware of the basic provisions of the relevant law
- you think customer support staff on minimum wage has any sort of legal training? The news are full of very wealthy people with access to star lawyers doing very stupid things (see: Elon Musk forcing himself to buy Twitter, Sam Bankman-Fried making public incriminating statements on Twitter, etc. and those are just the recent examples).