FAULTY PHONE (NOKIA C10)

I bought a Nokia C10 on the 27th September 2021, the phone is slow and looses internet connection most of the time. I took it back to the shop Ackermans in Vincent all the way from Mdantsane were I stay on the 2nd October 2021, cashier told me the manager will be inn the shop on Monday I must come back. he also tried to check the settings but the phone was only for that 5min on 3G then back to no internet connection. Today I went back to the Ackermans shop in Vincent spoke to the manager. she called the head office they told her they cant just refund me. they must check the phone if it got network I stood there from 9am till 11am trying to download what's up. but they say the network is fine. the phone is still slow and it is with in my 7days which they say if you find fault with in the 7 days they will give you refund or a new phone. I has the receipts and all but I came back with the same phone giving me the same problem. They refuse to take it back, had to pay parking ticket of R15 for the long hours they made me wait for nothing.