drilling very hard tiles please help !!

[supergas]

hi all i fit bathroons for a showroom and have come up against some very hard tiles lately that my regular drill bit will not touch i normally use the multicomstruction drill bits from screwfix etc the ones that go through any masonary without hammer they also go through metal and wood but barely touch these tiles also tried a few other bits i have but no luck
any help would be highly apprechiated.
Rich

 

[ajstoneservices]

These will work and can be bought cheaper on fleabay
http://www.screwfix.com/prods/57819/Drill-Bits/Tile-Drills/DeWalt-7mm-Diamond-Tile-Drill-Bit

 

[supergas]

cheers fella ill get 1 of these in mornin