Unreasonable excuse for faulty products between PEP and DStv

Good day

I went to PEP CLOTHING STORE this morning regarding a Dstv explora that I bought on the 29 December 2021 and still have the proof of payment with to exchange it because it's making weird sounds unfortunately I was told I have to add more money due to price increase or can take it to Randburg Multichoice which is impossible for me,I asked the sales Assistant of why the aren't they price matching it she said she'll ask her manager about.I don't think I really want to go back to the store because this is the second decoder doing the same and their attitude seems unwelcoming.I understand that they having partnership with Multichoice but however they need to be able to solve the situation not send me to Multichoice or tell me to pay more I know my rights that the exchange had to be price matched with the proof of payment I have.