The Black Friday protest was targeted on the company's busiest day and the police were called at 4am.
A number of specialist officers attended the scene at Power Station Road and a Section 34 dispersal order (under the Anti-Social Behaviour, Crime and Policing Act) was enacted at 6pm on Friday and remains in place.
The order allows police to disperse people from the area if they are involved in instances of anti-social behaviour and take anyone under 16 back to their home.
Chief Superintendent Elliott Sharrard-Williams said: "The role of the police service in these matters is to be impartial and not to have, or express, a view on the matters that are the subject of the protest.
“The responsibility of the police is to balance the rights of individuals to protest, against the rights of those whose activities are impacted upon by the protestors.
“Often the rights of these different groups can come into conflict and our role is to judge where that balance lies in ever-changing circumstances."
He added: “Our response to the protests will always be based on the available information we have at the time and officers will continue its engagement with the local community and all parties impacted by the issue.
“I would like to thank those affected for their patience and cooperation.”
The protest concluded at 9.30pm on Friday.
A total of 12 men and five women were arrested on suspicion of aggravated trespass and remain in police custody while inquiries continue.
They include a 54-year-old woman from Birmingham; 73-year-old man from Birmingham; 58-year-old man from Birmingham; 69-year-old man from Dudley; 19-year-old woman from Manchester; 23-year-old woman from Manchester; 19-year-old man from Manchester; 22-year-old man from Manchester; 20-year-old man from Bristol; 21-year-old man from Bristol; 31-year-old woman of no-fixed-abode; 22-year-old-man of no-fixed-abode; 31-year-old man of no-fixed-abode; 29-year-old man of no-fixed-abode; 42-year-old man from Nottingham; 25-year-old man from York and a 30-year-old woman from Buckinghamshire.