Big Easy complaint: Bad customer service

I brought my son to the big easy canary Wharf yesterday for his birthday and we was extremally disappointed . we was a party of 5 and was meant to be seated at 3.30 booked this time as we had other plans at 6pm .
we wasn’t seated until 3.50 kept being told they was preparing a table that had 2 glasses on it ? my sons starter had to be sent back due to the muscle shells disintegrated when he was trying to eat them as they had clearly been left under a heat lamp to long .every drink we wanted we had to call the waitress as she was not coming and asking us .we waited till 5.20 to get our dinner which is not good when a 3.30 table was booked the food was cold 2 dishes had to be sent back . we had to ask for our bill 3 times I feel this experience left us all in a bad mood left us rushing to our next destination and spoilt my sons birthday I’m really upset ,