Hi
Before getting onto some replacement act on ur WIC Card if possible would suggest to do some troubleshooting on ur cards.
Can u get the normal working link onto the suspected wic card and check whether you are still geting CTS down ?
Also you can swap the cards between the slots and check ?
did u chek up ur line which is getting connected to the WIC card ?
i did face similar kinda probs few years back but that was with a E1 link and WIC-2T which we solved in coordination with TELCO.
regds