Trouble with a roofer

I had my house re-roofed 4 years ago with a 10 year guarantee. I have had them back at least 4 times to see to water getting in. They always moan, but if I ring enough times, it gets done. While I was away last week (and incidentally last month too) there were torrential downpours and water got in via the highest part of the guttering. This is probably the only such serious downpours since they were fitted. I think that the high point is either too high or the 'drop' not enough. However can I expect them to come again and fix them under the guarantee? The house is Victorian terrace and the builders use the FMB logo on their notepaper.