My phone says prepaid service disabled
You haven't given much information here, so I'll have to guess. If your airtime has expired, then perhaps re-activating the phone will allow you to use it again. Note that you will need to add airtime when reactivating service.
If it's a newly bought refurbished LG 200C, and you are not able to activate service, then you need to call customer service from a landline or other cell phone. Customer service can check if everything is okay with the phone. If not, then they'll either send you a new phone or new sim card to fix it