So many young Thais do that when they get their first job, get all the cards they can and max them out.
I think it's actually best to engage with the process rather than just ignore. If a court date is issued, then there's a chance for negotiations. There are limits on the period credit companies have to start the process of recovering the debt but they usually seem to start action just when the limit is up. I know a couple of people now in their 30s who ignored all documents that were sent to their home address in the provinces and it's caught up with them eventually. Though they'd missed out on the court-mediated negotiation, they've still had offers of deadlines to make fairly lowball final payments. One works in a bank, and she just couldn't even afford those payments, so the court eventually ordered salary deductions, which was dealt with through her company and she found out from her HR people. There are some protections. I think, for example, that total deductions are not allowed to leave her with less than 20,000 baht a month. So it becomes a queue, with the credit companies having to wait their turns.
There's some very good information online in Thai, which I went through with my friend in the bank because she had no idea of what should happen. But it's gradually working out for her. Not quite as much as your wife has run up but not far off.