Your post is a bit unclear.
Do you have no signal at all or an intermittent signal?
When was it all working OK last?
Did anything change on the phone in the meantime - e.g. software/settings updates, factory reset, new phone etc.?
Is anything working - calls, texts, mobile data?
Did you ever configure your APN settings for mobile data access?
Text "APN" to 50048 and follow the instructions to do this:
Maybe you should try a replacement SIM in case your existing SIM is faulty or failing?
If you need to contact 48 support about this then see the links in my signature below.
