Have a look at the Town Hall website - the site won't allow me to post the link! So just search for Ayuntamiento Fuente Alamo. There's a section labelled 'Town Hall' and that contains a sub page with phone numbers and addresses. On that page is an email link for contact on revenue matters.
In the past I've used Google Translate to ask a question via this website - don't try asking in English. I guess you could give them your address at Hacienda and ask if you can set up a direct debit to pay the IBI. When we set ours up I queued to pay our IBI and then asked the official if it could be paid in future by direct debit. He took our bank details, and ever since then it's worked fine by DD every year.
Good luck!