Pausing between phone number and extension

I know that when I enter contact information I can specify a number and extension like 555-555-5555,,1111 to get a pause and then dial the extension. Works fine.

What doesn't work is I use a contact manager app from ZOHO. It shows me contacts and phone numbers. If I click on a phone number with an extension, the iPhone dials and I get a message from Verizon saying the number can't be dialed.

I would assume it is an error with ZOHO, except my colleague uses the same program on his android phone with Verizon and it works perfectly.

I don't think there is a solution but I thought I would ask.

I've never used ZOHO so can't really comment if it's at fault. What I was going to suggest is if you had tried using the contacts app from OS X to see if the same problem occurs?