The region usually runs about 1,200 trains on a Saturday but this was cut to around 600, leaving passengers frustrated on one of the busiest shopping days.
Trains to Wolverhampton, Shrewsbury, Stafford, Dudley, Kidderminster, Walsall, Smethwick and Birmingham were affected by Saturday's industrial action.
Rail bosses said they operated a "reduced but robust" service despite the disruption by West Midlands Trains workers.
An emergency timetable was in operation across the region in a bid to keep passengers on the move in the run-up to Christmas.
But Jan Chaudhry-van der Velde, managing director of West Midlands Trains, said: "This industrial action is entirely unnecessary. We have never proposed driver-only operation. We are committed to keeping a safety-critical conductor on every passenger train.
"The action is benefitting nobody and has caused major inconvenience to passengers and businesses.
"I would also like to thank those members of staff who have been in work today, many of whom have made personal sacrifices to help keep as many people as possible on the move.
“More industrial action is scheduled but we remain determined to find a way of resolving this dispute without further disruption and inconvenience for our passengers."
Rail chiefs planned for the disruption with some customers even emailed last week and given the option of a refund instead of travelling.
Unions, who mounted picket lines outside stations, blamed the disruption on West Midlands Trains' "refusal to agree to the safest possible means of operation"
A spokesman said: "We will not allow the drive for profit to override the core issue of safe and accessible services for all on West Midlands Trains and we stand firm on that very basic principle.
"We will never compromise on the issues of passenger safety and accessibility."