How arey they supposed to know how many beer lao you've drank and ladies entertained in those five days?? They need to make sure you still have some left for Thai ladies
'travelled back and forth to see her'. If you've never lived together she's definitely NOT your GF lol, not only yours anyways ;) use your head, the one that is on your shoulders...
if you mean border run then no, you can't get any visa, you can get a visa exempt, if they'll give it to you of course, which isn't granted, especially, if you try to cross back on the same day.
Sounds like they need money to buy lanterns...it's on the hotel, not you, don't go there, go to some hostel rent a bed and make sure they've registered you.