No carbonation :(

First batch of cider but have brewed 1/2 dozen beers without problems in the past. Used recipe from online which called for 5 gallon glass carboy filled with standard Great Value apple juice from Wally World. Used White Lab cider yeast at 72 degrees and the thing went crazy for 5 days and kept right on bubbling for 5 weeks. After 6 weeks, all bubbling stopped, racked into bucket and added a cup of corn sugar. Stirred and bottled crystal clear cider and left all yeast (about 1/3 inch) on bottom. After 12 days at 68-70 degrees, tried one bottle to see how carbonation was coming and FLAT, FLAT, FLAT. Absolutely no carbonation but tasted good. I didn’t do any OG or FG readings. I am thinking of 1.)Warming to 72 and waiting another 2 weeks. OR 2.) Ordering more yeast, adding a few drops to each bottle with a corn sugar pellet or two and recapping. OR 3.) Pretending I made some good apple wine.
ANY SUGGESTIONS???

Take a FG reading, and also see if the cider tastes dry or is still a little sweet. If sweet, or if FG is above 1.010, chances are your yeast died from alcohol poisoning, and they are not going to carbonate the bottles. Also, post your recipe. How much juice and how much sugar did you use?

PATIENCE! Cider takes at least 3 weeks if not 4 or more to carbonate. Patience. I can almost promise you, it will carbonate just fine in time. Keep it at room temperature and this will help speed things up as fast as possible.

FG 1.000 and semi dry to dry. Can’t find original recipe. I now remember adding 2 cans of frozen white grape juice concentrate to the fermenter as suggested by a friend to boost alcohol content.

If it is 1.000, it is unlikely the yeast all died from alcohol poisoning, and it should carbonate fine. Give it some more time. Just to be sure, the recipe didn’t call for adding campden tablets, potasium bisulfate, potasium sorbate or anything similar did it? If yes, you won’t get carbonation.