holiday in may

I have booked with ICR for my holiday in May but I booked a flight only with TC. For over a week now I have been trying to phone them at their suggestion to book wheelchair assistance and to book my walking frame on as additional luggage. I have listened to all their excuses on a dial a disc, eg updating their computer system, experiencing high volume of calls etc.I had enough difficulty making the flight booking and am not confident enough to chance trying to make these additional requests on the web. Is anyone else having problems getting through? I know I will have to pay an additional charge.