They Rain Sim Card stopped receiving network coverage after activating the Unlimited off peak.

After ordering and activating my sim card, it worked well with 50c/mb until i tried to activate the unlimited off peak data. After activating it, I couldn't use my sim card (it had no network coverage at all) and I tried it on different devices with no luck. The explanation I got when communicating to one of the consultants was that "your area has no coverage". How is this possible? Firstly, I have been using the sim for 4 months at the exact same location, which they claim has no coverage. Secondly, I have another Rain sim card which works perfectly at the same location.

I failed to get an answer to why my sim card is not working, because the reasoning of "network coverage" is not true. And why am I only experiencing this problem only after activating the unlimited off peak? Is it because it's a service they charge for activation and not usage, meaning whether I can or cannot use the service, I'll have to pay end of the month.