False advertising

I have been a client of Mweb's for many years and moved to fiber just before the lockdown in January 2020. Mweb is now advertising a 25% discount on their fiber packages, for which I app****, however was informed that due to being an existing client and having qualified for free installation and router nearly 3 years ago, I do not qualify for the special offer. From having looked at other providers you are only liable to pay some costs if you cancel your subscription before 12 months have expired, yet MWeb are telling me I benefited in the past, nearly 3 years ago I am not allowed to benefit now. Shall I cancel my account after having been a subscriber with Mweb since 1995, has really left a bad taste in my mouth as the application was approved and then cancelled and advised accordingly by the rudest MWeb representative...........Stink on you MWeb, disgusting, after 27 years of being a subscriber...stink on you