How to migrate potentials to existing contacts?

Hey Guys

I am new to ZOHO and this may seem like a really dumb question, but I am hoping someone can help me...

I have two CSV files of which I wish to import into ZOHO.

The first CSV file of which I wish to import into the ZOHO Contact Module, has the basic details of which are
First Name Last Name Account Number ConactID Cellular Phone Email Addresses

The second CSV file which i wish to import into the potentials module has the following information
Conf Number Charter Date Duration Account Number ConactID Contact Name Car Opportunity Name Date Time Created Booking Status Amount Opportunity Stage Potenial ID

After contacting ZOHO support, they advised that I should create a ContactID column in each file so that upon import the potentials will match up with the correct contact.

I did this and it did not work...

I have attached two test files with dummy data.

So I am seeking some help please :)

Regards George