4G has bad coverage in my area

I spoke with your consultant via Instagram on Sunday regarding how slow the 4G sim card is and asked if it could be returned for a 5G if possible because the purchase is still valid, 7 days has not lapsed. On 21/11/2022 the agent promised via Instagram that I would get contacted ***). When I made the 4G sim I was informed that both Fleurhof and Meadowlands had good network coverage, but I am experiencing frustration. I have to attended online classes, but I can't be due to this issue.