As already stated....DONT LET HER BULLY YOU. You have the right to attempt re-stretch of the carpets. She can still open as usual even with the carpets having shrinkage. It may be a good idea to use tape to tape down & make safe the carpet at the door bar. This will cover yourself & the owner of trip hazzard. Its good that the fitter cant get there straight away. Also again as stated you will NOT have to pay FULL replacement cost. Ask the owner where & when she bought the carpets & if possible ask to see the reciept. The fact that the property is used for business purposes means she WILL HAVE somewhere either reciepts or other means of eveidence as to when , where & how much the carpets cost her. She says it was about £2500, i bet that wasa for the carpets, underlay, gipper, door bars & fitting. This all adds up to £2500 so you will probably find that the actual carpets where not anywhere near the £2500 that she has mentioned. If this is the case then its not as bad as it sounds if replacement is required as you wont need to replace the gripper , underlay or doorbars. Then taking into account the % to be deducted due to age & wear of the carpets.
REMEMBER, DONT LET HER RUSH OR BULLY YOU. IF THE CARPET DOES REQUIRE REPLACEMENT CUT A PIECE OFF AND TAKE IT TO A CARPET SHOP & GET A QUOTE. IF ANY OF THE ROOMS THAT SHRUNK ARE SMALLER THAN 1 OF THE OTHERS THEN USE A SHRUNK CARPET & REFIT IT INTO THE SMALLER ROOM.
Richie.