SAN BRUNO, Calif. (KGO) — Imagine you walk into a store, buy a couple of items — and instead of leaving a $5 tip, you later learn an extra three zeros were tacked onto your bill. Your $5 tip just became $5,000. And it’s ‘unable to be voided.’

It happened to Peninsula resident Linda Mathiesen. She struggles with a shoulder issue and went to a San Bruno vape store to purchase “CBD relief gel” to ease her pain.

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Receipts show the total for her items was $129.28.

Feeling generous — yet short at the tall checkout stand — she left what she thought was a $5 tip.

“He says enter a tip — so I did… I push what I thought was only two zeros. Ended up being three zeros,” Mathiesen said. “But, there’s no decimal point… I’m like, ‘WAIT! I want to delete this!”

Instead of voiding the transaction, receipts show the clerk at ‘San Bruno Exotic’ processed a tip for $5,000.

Mathiesen says she pleaded for him to reverse it, but at first he claimed he “couldn’t.”

“He said he didn’t know how,” Mathiesen said, adding the clerk later told her the shop never received the money.

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But that’s not what her bank statements showed.

“He never erased it – nothing!” Mathiesen said. “I was livid.”

It left Mathiesen in a state of panic. She is a special education teacher living on a fixed income.

“Who would ever?” asked Mathiesen. “Like, $5,000?! I don’t have that kind of money!”

“How many times did you reach out to Wells Fargo?” asked 7 On Your Side’s Stephanie Sierra.

“22 times… each time two hours on the phone,” said Mathiesen.

Mathiesen tried to dispute the transaction the same day this all happened. After dozens of attempts to reach Wells Fargo, she says the bank did nothing. It wasn’t until eight months later, records show Wells Fargo tried to close the case, saying “too much time had passed.”

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According to Wells Fargo, disputes are typically required to be filed within 60 days of the transaction date. The bank claims to offer “zero liability protection” to protect consumers from fraudulent transactions that are reported promptly.

Yet none of that happened for Mathiesen, a 30-year customer of Wells Fargo.

“I literally called them within five minutes of being in the store,” said Mathiesen.

Instead, nearly a year later, the transaction continues to haunt her. She’s living in a pile of paperwork — now facing interest payments on the exorbitant tip.

“I busted out in tears… I’m a single mom, I have two grown kids… and I explained to them, ‘I’m sorry,'” she said, tearing up. “My son is graduating college next week… and I can’t even buy anything for him because I have $5,000 outstanding… now it’s $5,500!”

7 On Your Side reached out to Wells Fargo for further comment, and the bank quickly responded to Mathiesen, vowing to refund the total $5,000 tip amount plus interest.

“I’m so relieved!” said Mathiesen.

In the meantime, 7 On Your Side visited San Bruno Exotic, which now goes by Exotic Vapes. The clerk working there now told us new owners took over in January. While he’s aware of this situation and believes it should be handled with the bank, he had “no comment.” According to the business, the owners of Exotic Vapes also own Exotic Puff N Stuff in San Bruno.

Take a look at more stories and videos by 7 On Your Side.

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