False advertising

I have registered for their rewards and on the 4th March 2021 I have claimed an anniversary upgrade reward and was informed via email and sms that it will be effective after my next billing date of which is the 1st of April. I have been in contact with them via telephone and email since after my billing date and the last person that I spoke to made me loose hope that my upgrade will be allocated to me. She told me that it doesn't show on their system even though I sent them proof of email several times wasting my airtime and data. No one ever cared to come back to me and resolve my issue.