Condenser heater harness not defrosting.

Samsung Fridge;

Fridge side keeps icing up about once every 2 months and fan blades make contact with built up ice on defrost heater harness and makes clicking noise - I changed the heater harness about 2 years ago but it failed again and don’t want to repeat the process.  Fridge specialist came twice to look at problem and cldn’t fix it, he even contacted Samsung helpdesk and they said no way to fix it and should buy a new Fridge !!!  Now when it gets ice build up on condenser and heater harness I just take my heat gun to it and melt the ice buildup and replace the cover and its ok for about 2-3 months until the ice builds up again, Iv’e got it down to about 1hr to remove cover panel and defrost and put it back again.  Do you have any suggestions on how to avoid ice build up on condenser blades and heater harness other than replacing harness again, which was a waste of time the first time I did it.

Thanks; John.