One line queue with only 3 cashiers on a Sunday 25

I went to the store on Friday walked out, Saturday walked out again eventually went in on Saturday ...I don't know who's idea it was to make one line queue but it's stupid and definitely not good for customer service ....from standing in the queue I at least saw about 10 people turning out of the queue as the queue was turning right to the back in the aisle of the bathroom equipment just also to see 3 cashiers on the tills which only one had a packer clearly you are losing clients .....besides the queues there is also never stock of promotional items...even though you can get a call back voucher you not reimbursing clients for petrol spend...Please look into getting customer service up to standard as they are the most valuable asset for your business