Agree with @crispyoz's recommendation to clean the contacts. If it were a hardware issue or manufacturing defect, it likely wouldn't have worked at all. I also recommend checking if the contacts have been damaged during SIM card insertion and removal.

I realized a GSM module with Omega 2+, maybe this can help you: https://github.com/AlbertoZandara/Onion-GSM-Module

You would have to look at the datasheet. It has 2 serial interfaces. I assume one of the serial interfaces is for data transfer while the other is for control. So, if you use serial to USB converters, you should be able to connect both to an USB hub and connect the hub to the onion.