Curly handset cords, old or new, have a nasty habit of getting tangled up.
It's quite easy to work the twists out but the coils rarely seem to lay properly afterwards.
A way of at least improving things is to wrap the cord around a metal bar and then pour a kettleful of boiling water over it. This is also a good chance to clean it by attacking it with a soapy nailbrush.
After that run it under the cold tap and remove the bar.