Can't login to make subscription payment

We have received the following email on an ex-employee's email account

We are delivering this message to tamsin.dace@planningshopintl.com.
Dear Tamsin Dace,
We could not charge your credit card for your Prezi subscription.
Prezi Pro Subscription
Card: Visa **** **** **** 0705
Amount: 159.00 USD
We will try to charge your card again. After trying three times,
your account will expire and you will be unable to edit your prezis.
In case you wish to change plans, please visit this link: http://prezi.com/profile/upgrade/
To cancel your subscription, use the following link: http://prezi.com/profile/unsubscribe/
Happy zooming!
Prezi team

We wish to pay the subscription but the company credit card details have since changed and the former employee hasn't left a record of the login details so we can't do this as of yet.

Could you please let me know how we can reset out login details to avoid our subscription being cancelled so we can login and make the payment.

Thanks.