FNB SIM card pathetic. No data connection at all. No help from FNB

I recently got the FNB connect SIM card. For the first week; the SIM card worked perfectly and I had perfect signal. After a week of using the SIM card, it doesn’t work! I can have full signal bars on my phone, but my data refuses to work. I can’t use WhatsApp, let alone any other apps without wifi. My I have an iPhone XS Max but my data with FNB constantly stays on “EDGE”, it doesn’t even go to “3G”. there is no service - no data connection - at all. I can’t even access my FNB app with the data. This is extremely problematic. Data coverage also very weak and volitile. I called FNB mutilple times and all they told was to reset my phone using *147# and reset the settings. I did that multiple times and still no data connection. Honestly so pathetic and I’m so disappointed in FNB. What a damn *******.