Passengers aboard a Comtel Air charter flight from Vienna to Birmingham, England, say they were asked to pay a total of $30,000 for fuel for the trip. The passengers say they were asked for the money during a refueling stop Tuesday night in Vienna on the last leg of a flight from Amritsar, India, to Birmingham, the BBC reported. The Austrian airline said it was investigating. Bhunpinder Kandra, director of passenger services for Comtel, said: \"I have heard what happened, it shouldn\'t have happened and I will investigate why it happened. The people who had to pay the money will receive a refund.\" If passengers didn\'t have the money to pitch in for fuel, they were told to leave the plane, one by one, to withdraw cash in Vienna, passenger Reena Rindi told Channel 4 News. Rindi, who was traveling with her 2-year-old daughter, said she and other passengers agreed to pay about $200 each to fly to Birmingham. Comtel contracted in October with Spanish carrier Mint Lineas Aereas to operate the service between Birmingham and Amritsar. MLA said Thursday it had stopped operating as a carrier for Comtel. Comtel said English travel agents had not paid what they owed, which is why it had not paid MLA since last month. In a statement Thursday, MLA said, \"Due to unresolved financial questions, it was decided by Mint Lineas Aereas as operating carrier to stop operations for Comtel Air.\"