Slowest Internet

Received my 19hr SIM and it worked great for a day. The day after the speed dropped so bad that I had to revert to using my Vodacom and MTN cards. It is especially bad during the day which is a huge issue for me seeing that I work from home due to the current lock down. Tried the online chat and all they mention is APN settings. No explination on what the issue is and the plan to fix it. The speed have been up and down the whole time, but being VERY SLOW seems to be the norm....