Can you share the results of these below? Are you taking regular transaction log backups?
select name, log_reuse_wait_desc from sys.databases
DBCC OPENTRAN()
You need to properly size the transaction logs so that auto grow won't be kicked in and frequently shrinking them is NOT a good idea.
EDIT: Code based on your comments to check which log files grew recently.
DECLARE @filename VARCHAR(255)
SELECT @FileName = SUBSTRING(path, 0, LEN(path)-CHARINDEX('\', REVERSE(path))+1) + '\Log.trc'
FROM sys.traces
WHERE is_default = 1;
--Check if the data and log files auto-growed. Look for tempdb, log files etc.
SELECT
gt.ServerName
, gt.DatabaseName
, gt.TextData
, gt.StartTime
, gt.Success
, gt.HostName
, gt.NTUserName
, gt.NTDomainName
, gt.ApplicationName
, gt.LoginName
FROM [fn_trace_gettable](@filename, DEFAULT) gt
JOIN sys.trace_events te ON gt.EventClass = te.trace_event_id
WHERE EventClass in ( 92, 93 ) --'Data File Auto Grow', 'Log File Auto Grow'
ORDER BY StartTime;