Innocent Foods sells cold-pressed juices, organic, gluten-free, sugar-free and dairy-free foods, and "all sorts of yummy, delicious, innocent things".
The couple have been given a deadline of November 16 to cease all use of the word in their operations, which could cost them about $7000.
The cost of taking down or removing signs, labels and merchandise was not huge, but replacing it with a new name would be another story.
As well as that, the pair have paid two years in advance for their website domain, which cost $3000.
A trademark lawyer has told them their use of the word innocent was a clear breach.
Rientjes said the lawyer for AJ Park intellectual property firm, which the letter came from, has not been to visit them, despite being on the same street.
"We've been trying to contact him to try and make our job rebranding as easy as possible for ourselves and for them, but they're not being very helpful."
Rientjes and Yeter were using the Innocent Foods name before Innocent was trademarked, but hadn't gotten around to trademarking it themselves as they couldn't afford it at the time.
Before opening their cafe, they checked to see if the trademark was available, but didn't realise Coca-Cola's application was pending.
She said their "naivety" could have contributed.
"It's our first business and we're trying to do everything on our own."
The ordeal has left her "pretty overwhelmed". Dealing with the rebranding as well as working 70-hour weeks running the store was "really hard".
She wanted to raise awareness about the "corporate bullying" they were experiencing.
AJ Park's Wellington managing director Damian Broadley would not comment without speaking to his client first.
