I think this starts with: what is your intended support path for customers?
There are several different possible rationales that I can think of for having two contact methods:
- Catering to customer preference - the two are basically equivalent, and the customer can choose whichever they like (and once choosing one they are unlikely to switch to the other contact mode).
- Different methods based on urgency - phone calls are for more urgent query
- Email as preferred mode, with phone calls as a fall-back. - If the email is not able to answer a customer's question, speaking on the phone can solve the issue.
Another issue here is: Do you need to capture the same information in each case?
For an email enquiry, you need to get all of the information up front to answer the question, but a phone conversation allows more information to be obtained on the phone. So it may imply different forms are needed.
I think if you clarify the support path and the information requirements, what to do about the forms should become clear.
Ultimately, whether one form or two exists on the website is irrelevant to the user, but the user should be presented with a clear path and options to get needed support; there shouldn't be multiple paths that make it unclear which one should be selected.