Online it service for business - expense deductible?

Hi,

In my business, we are using an online service called "zendesk" (www.zendesk.com) that costs $120 each month. It is paid via credit card automatically and billed to our company. Zendesk is a US based company...

Is this deductible as expense in IT? 

I have read that as per Income tax rules, all foreign payment is to be made with TDS or its disallowed... but there is no way to make any deduction as its online service and fully paid by credit card each month...so please advice on the same. As the amount is working out to more than Rs 1 lac per year and full scope is used for business only. 

Thanks in advance, 

Arun