When using PartyPoker we didn't have any major issues so we haven't had to use their support very often - and of course the best kind of support is when you don't need any.
You can contact their customer service people by telephone or email although when we interviewed long-time players we learned that they has disabled their live online chat feature – so they stand accused of cutting corners here! The 24/7-telephone support does often respond in under a minute, which is quite impressive - although email, response times are often longer than the advertised 24 hours.
Depositing into and withdrawing from Party is very quick, simple and secure via Visa/Mastercard/UK debit cards (Switch/Maestro/Solo)/ NETeller/FirePay and Western Union, so you have plenty of options – unless you only have an Electron card!