As a Turkish liberal who does not support conservatives and as a voter who spent many times watching the opposition speeches my answer is: It depends what you call cheating.
If you mean stealing votes or adding more votes than there are, then as the liberal opposition candidate Mr. Ince said, "no". Even though there were some reports of illegal actions going on, the difference in votes was ~10 million votes, which is thousand times more than the possible illegal things which might happened.
But meanwhile the president Mr. Erdoğan used all government resources (like planes etc... which of course we liberals also pay with our taxes) opposition mostly run their campaign with our donations. Many TV channels didn't give screen time to opposition leaders. Since not only public but also most of the private media is under Mr. Erdoğan's control, it was totally unfair. "Doğan Media", probably Turkey's biggest media organisation, which was the last media organization which didn't support any group directly was sold to an Erdoğan supporter recently.
Please use google translate to see the time distribution between opposition and Mr. Erdoğan in government public TV.
Bottom line: The AKP get ~40 hours all other opposition get only ~3 hours. It is much more worse in government controlled private media.
There were more things which I think were totally unfair (like election being run while martial law is going on etc...). But I don't want to nag about them.
As a proud Turkish citizen I still respect conservatives I hope these things will be more fair in the future. These are our problems which we have to solve ourselves. Also despite unfair things, we should self criticize as liberals. We have to work harder and also try to anticipate and understand our conservative citizens.