Cresta Jewellers stupid or negligent

I recently took three of my watches to have new battery's put in. A TW Steel A1GP chronograph a Vagary AquaDiver & a Roamer Power 8. All of these watches are clearly marked water Resistant to various degrees, minimum 100 meters. All have had their battery's replaced before with no problems. I received them all back working then left to the coast on holiday. I was wearing the TW Steel to the beach, I spent ten minutes playing in the surf with my children. When I looked at my watch it was full of water. I immediately phoned Cresta Jewellers & asked what I should I do,I was advised to leave it & bring it back when I was back. This is completely wrong it should have been stripped immediately apparently. When I returned Cresta Jewellers told me it is not their problem & I should take the watch to someone else to be repaired as well as the other two they had changed the batteries on as it was likely to happen to them as well as they had not replaced any seals when they opened them. I was never told that they could not guarantee they would be water resistant when returned. One of them is my dive watch & clearly marked DIVE. I am shocked at the lack of service and integrity shown.