As said above communication is key to a haircut. Did you ask for a number five on top and a number two on the sides? If so then fair enough you’ve every reason to go back and ask them (calmly if possible) to rectify it, although this would have been better done at the end of the haircut.
I’ve twenty five years experience as a barber and its almost impossible to please everyone but i’ll always try my best to get it right.In this case your hair was left longer then desired and that can be sorted fairly easy, give the shop the opportunity to fix it for you, they will appreciate it.
It constantly amazes me how many people don’t actually know how their hair is cut when asked. “oh i just get a trim” to me a trim is five mm to 10 mm off all over.. for others its virtually a restyle.
There’s price points for everyone and clipper cuts shouldn’t be anymore than a tenner or less unkless you are getting it washed too, buts its insulting when people think that a good service can be achieved on a full haircut for 6-7 quid.
I’ve yet to see anyone who can provide a good high skilled service at low prices as its high volume ten mins a haircut bish bash bosh.