Revd Wena Parry was told her insurance with Age UK may not be valid because she had put "Christ Must Be Saviour" and "Christ For Me" on the front and side of her car.
The 75 year old from Cymmer near Neath Port Talbot told Premier she believed it was religious persecution.
She only found out the stickers could have invalidated her policy after a part from her car was stolen.
When she sent images to Age UK as part of her claim it told her the slogans counted as a modification and she should have declared them.
In a letter the company said: "These modifications do not fit our acceptance criteria for motor insurance and cover would have been declined if we had been made aware of these at the time of purchasing your policy."
Revd Parry told Premier it was 'insulting' to be told her stickers showing her faith were not allowed.
She said it was very important to her to be able to have the slogans there.
"All I'm trying to do is lift up the name of Jesus and let the Holy Spirit do the work," she said.
The minister said she was without a car for four months before Age UK agreed to pay out.
"If I go on a bus it takes me all day just to go shopping and I've got so much to do.
"But the Lord has kept me at home a lot and it's done my soul a lot of good, the quietness. There is stress," the 75 year old added.
Age UK told Premier: "We are very sorry that Reverend Parry was not happy with the initial outcome of her claim and the quality of communication she received. Ageas has since reviewed the claim and has now offered a settlement of £725 and has waived the £100 policy excess and outstanding direct debit balance as a goodwill gesture.
"While all car owners have the right to self-expression and to place whatever they wish on their cars, we would urge all drivers to make their insurance providers aware of any graphics applied to their cars.
"The situation regarding Reverend Parry's claim was in no way related to the Christian nature of her graphics.
"As a result of this case Ageas and Age UK will review how we obtain this type of information during the sales process to try and make it clearer for all customers at the outset."
Premier's Antony Bushfield speaking to Revd Wena Parry: