It only happens to a new tire. If they won’t I’d have them take it off, go home, patch it and put it back on myself. Our local farm store has patches with cords in them for strength, maybe some available on internet. You have nothing to lose, it’s junk the way it is and as you say it only goes a few miles an hour.

your a busy man Mr Tom...

You could always try an inner tube if they don’t patch it😀🇨🇦

Two things for you you had trouble from day one with the ramp ant no good with a 2 wheel rig make it a full size ramp like a landscapers trailer ,Next if tire shop wont fix the tire get blow out patches put one on the inside of the tire then foam fill that tire