Dodgy Contract - Security Officer G4S Employee Review

Contract is designed in a dodgy way, They can sack you anytime or can give you one week notice but you have to give them at least 4 weeks notice from the date of joining. They promise that it's guranteed 40 hours per week but base it on several weeks that is 13 weeks. so even if you think you have a 40 hours contract and you worked 60 hours and you are happy that you got 20 hours in overtime, they can deduct those 20 extra hours in next monthly salary if they don't give you extra hours. They want you to be available 24/7 so they can call you anytime and expect you to work as they want and so you have no work life balance.