Hi,
What did the repair shop actually repair? (What was it in for?)
If the engine is run on full choke yes it will damage the engine but as to whether or not it is actually ON full choke is another question - if you have adjusted the throttle cable it may well not actually be activating the choke butterfly. When you were using it was it blowing black smoke? My advise is take it back to the repair shop. The problem is probably in the adjustment of the cable and/or inside the carby.
Possibly an oversight from the repairer or they got the apprentice to do the work.
Also
Pete
